《浅析使用有限元分析的注射模具设计.docx》由会员分享，可在线阅读，更多相关《浅析使用有限元分析的注射模具设计.docx（14页珍藏版）》请在三一办公上搜索。
1、使用有限元分析的注射模具设计摘要归功于电脑模拟分析运用，通过Moldflow模流分析仿真系统几个步骤就可以对塑件及模具进行开发。基于注塑模具的仿真结果是在Pro/E 三维辅助设计的帮助下完成的。计算机辅助工程的运用产品的开发阶段尤为突出，这也使得工具及模具的成本减少。关键词：注射模具，CAE仿真，Moldflow1.介绍塑料的最常见的处理方法之一是注塑。这一进程的主要优点包括其在塑造的各种产品的多功能性，它的自动化可以引进，高的生产率和较小的物件公差与制造的可能性。 注射成型件的生产与注塑机和注塑模具一起进展。相对于形状复杂的零件等的生产方法，这个过程运行在相对短的周期。注塑标准的要求是： 高
2、精确度和型腔表面光洁度 最大刚度，模具组件的强度，整个注射模具可抵抗夹紧力，注塑压力 适当的浇注系统，注射系统，排气系统和冷却系统 最佳生命周期。 注射模具设计师的任务是： 分析成型零件的设计，考虑形状、尺寸、浇口位置和零件回弹 确定分型面，考虑功能和成型零件的外观，定义型腔草图 确定模腔数，模腔尺寸及布局和考虑收缩，几何公差，及注塑机 选择适当的浇注系统，冷却和通风系统 对模架选择材料和其他研究过程中加载的条件和模具组件注塑周期。 选择合适的注塑机。 现在注射成型技术的制图不适合用二维绘图来描述复杂的形状。使用三维CAD模型的确切原因是确切描述部件形状，很容易看到剖面图及细节图。更重要的原因
3、，使用三维CAD模型可以利用CAM软件对注塑和模具制造的过程仿真。 （2）为CAM使用三维CAD模型已成为模具制造的一个组成部分。 （4）辅助工程的注射成型过程模拟，逐步成为了模具制造过程的组成部分。随着CAE模拟模具设计人员的帮助可以测试未经注塑模具的使用前需要解决的各种费用及耗时模具的更正。2.注射模具过程仿真这部分是描述在Mlodflow模流分析6.0的帮助下的顶部注射情况。这次仿真的材料是Cycoloy C2100HF。分析准备的是有限元网格模型。常规计算来决定开始的模型尺寸。下一步的工作是执行流道优化分析，以减少流道系统的体积和重量。2.1由列线图决定分流道系统的尺寸这种方法属于常规
4、的电脑计算方法。输入型腔布置，部件材料与体积大小数据来决定分流道截面尺寸。型腔布置设计决定了分流道的形状，同样知道重量也决定了截面的尺寸。图2-1展示了型腔布置的地方： L 主流道的长度 L1 主分流道的一半长度 L2 副分流道的一半长度 L3 浇口长度图2-1. 型腔布置单个型腔的流道系统总长度：LC= L1+L2+L3 = 55 + 33, 5 + 15, 5 = 94 mm成型零件体积：V = 61000 mm3分流道系统的体积：VCA = 4298, 96 mm3材料密度(Cycoloy C2100HF): = 1,075 g.cm-3成型零件重量：G = Vk. = 61. 1,07
5、5 = 65, 57 g成型零件的壁厚：s = 2mm有了这些参数和列线图就可以确定梯形分流道截面尺寸。D的值是与分流道连接的主流道的直径，在图2-2用直线列表定义。Lf是分流道尺寸计算的修正因素。图2-2. 分流道尺寸确定列图数值线图：D= 3,8 mm , Lf=1,1, D= D. Lf = 3,8. 1,1 = 4,18 mm2.2为仿真准备模型基于这些有限元网格计算准备，为了在MPI 6.0（图2-3）中仿真。在模型中包含型腔、分流道系统、冷却流道和镶块。图2-3. 仿真模型分流道系统的优化由MPI/Flow模型来展示。分流道平衡分析被用来分流道系统体积的优化，当使用足够填充时的平衡
6、填充方式。3.分析结论主要的分析是47, 92%的分流道系统体积的减少输出。这也减少了材料的成本和周期。在图3-1，3-2中，是填充始时间与冷却时间的输出。基于这些数据是在模具没有制造与修复的前提下，在设计阶段中所必要的。图3-1. 填充时间分析图3-2. 冷却时间的分析4.模具结构在想要的流道分析输出后，基于有限元网格划分的3D CAD 模型被准备好（图4-1）。这个模型被输入CAM系统然后在CNC机床中制造模具。图4-1.3D CAD 模具装配Design of Injection Mould Using CAEAbstractThe contribution deals with sev
7、eral steps computer simulation application by means of CAE system Moldflow MPI in mould development for mold plastic part. Based on result of simulation design of injection mould is made with help of Pro/Engineer CAD system. Application of the CAE methods is accentuated in the development phase of t
8、he product, which redounds to cost reducing on tools and moulds development.Keywords: injection moulding, CAE simulation, Moldflow1 IntroductionOne of the most common processing methods for plastics is injection moulding. The major advantages of the process include its versatility in moulding a wide
9、 range of products, the ease with which automation can be introduced, the possibility of high production rates and the manufacture of articles with close tolerances.Production of injection molded parts is in progress with injection molding machine and injection mould. This process is running in rela
10、tively short cycles compared to other production methods for complex shape parts. Standard demands on injection mould are: High accuracy and cavity surface finish Maximal stiffness and strength of mould components and whole injection mould to resist clamping and injection pressures proper runner, ej
11、ection , venting and cooling system optimal life-time.Tasks for injection mould designer are: Analyze molded part design considering shape, dimensions, gate location and ejection of part define parting plane considering function and appearance of molded part, define drafts in cavity determine number
12、 of cavities, cavity layout and cavity dimensions considering shrinkage, geometry tolerance, wear of cavity and used injection molding machine select proper design of ejection, cooling and venting system select material for mould base and other mould components considering conditions and load during
13、injection molding cycle. choose tightening of mould on injection molding machine.Nowadays technical drawing of injection molded part is not sufficient to describe complex shapes in 2D drawing. Reason for using 3D CAD model are wide opportunities to exact describe shape of part, easy making of cut vi
14、ews and detail views. More important reason to use 3D CAD model is CAE process simulation of injection molding and mold manufacturing with CAM software. (2) Using 3D CAD model for CAM software has become integral part of mould manufacturing. (4) CAE process simulation of injection molding is becomin
15、g stepwise integral part of mould manufacturing process. With help of CAE simulation mould designer can test various construction solution of injection mould without need cost a time consuming mould corrections.2 Injection Molding Process SimulationIn this part of contribution is described analysis
16、of molded part injection (top part-hosuing) with help Moldflow Plastics Insight 6.0. Material proposed for this simulation is Cycoloy C2100HF. For analysis is prepared mould finite element mesh model. Start model dimensions is determined conventional calculation. In next step is performed runner opt
17、imization analysis, to reduce volume and weight of runner system.2.1 Determining dimension of runner system by nomogramsThis method belongs to conventional way of computing. Input data for determining runner cross section dimensions are cavity layout, material of molded part and volume of molded par
18、t. Cavity layout designed upon determines length of runner channels and with known weight are determined cross section dimensions. (1) Fig. 1 shows cavity layout where: L sprue length L1 half length of main runner L2 half length of secondary runner L3 gate length.Fig. 1 Cavity layoutOverall length o
19、f runner system to single cavity is:LC= L1+L2+L3 = 55 + 33, 5 + 15, 5 = 94 mmMolded part volume: V = 61000 mm3Runner system volume: VCA = 4298, 96 mm3Material density (Cycoloy C2100HF): = 1,075 g.cm-3Molded part volume: G = Vk. = 61. 1,075 = 65, 57 gWall thickness of molded part: s = 2mmWith this pa
20、rameters and nomograms are determined dimensions of trapezoidal cross section of runner channel.Value D is the diameter of sprue at hne connection with runner and is defined in nomogram (fig.2). Lf is correction factor for calculation of dimension of runner.Fig. 2 Nomograms for dimension determinati
21、on of runnerValues from nomograms: D= 3,8 mm , Lf=1,1, D= D. Lf = 3,8. 1,1 = 4,18 mm2.2 Preparing model for simulationBased on these calculations is prepared finite element mesh for simulation in MPI 6.0 (fig.3). This model involves cavity, runner system cooling channels and mold block.Fig. 3 Model
22、for simulationRunner system optimization is performed by MPI/Flow module. Runner balance analysis is used for runner system volume optimization, determine balanced filling pattern when using family moulds and sufficient filling and packing pressure. During analysis dimensions of runner system arevar
23、ied in selected constraints.3 Analysis ResultsMain analysis output is reduction of 47, 92% runner system volume. This reduces cost for material and cycle time. In the next Fig. 4, 5 is analysis output for filling time and time to freeze. Basic on this data can be made necessary modification in mould
24、 design, without need of manufacturing and repair mould.Fig. 4 Analysis of fill timeFig. 5 Analysis of time to freeze4 Mould ConstructionAfter running analysis with desired output, can be prepared 3D CAD model (fig.6) based on finite element model used for this analysis. This model is then input data for CAM system and manufacturing mould with CNC machine.Fig. 6 3D CAD model of complete mould assembly
